JPH06256853A - Jig for heat treatment of vessel and heat treatment working method of vessel - Google Patents

Abstract

PURPOSE:To improve a heat treatment working method, in which corrosion resistant strength of a vessel used in the condition filled with a corrosive material in the inner part of the vessel is improved, and to improve the utilizing efficiency of the necessary heat for heating by executing the heat treatment for forcedly cooling the inner surface of a locally heating part from the outside. CONSTITUTION:A jig 7 for heat treatment of the vessel 1 is formed with a heat insulating material and has a medium passage 15 for passing cooling medium (a). This tip part 16 in the flowing direction of the cooling medium (a) is positioned to near a heating means 4A and opened in between the outside surface around the medium passage 15 and the inner surface of the vessel 1 and, on the other hand, the upstream side is formed so as to have the closed gap 17. By this gap 17, the heat gain from the heating means to the locally heating part can be lowered than the conventional method and the utilizing efficiency of the heat can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment jig for a container and a heat treatment method for a container. The heat treatment jig for the container and the heat treatment for the container are suitable for facilitating cooling of the inner surface of the heat treatment of the container. Regarding processing method.

[0002]

2. Description of the Related Art A conventional heat treatment method is disclosed in JP-A-56-13.
No. 4022 publication. In both straight pipe heat treatment and bending of the pipe, nothing is placed inside the pipe corresponding to the local heating unit and heating is performed as it is, and the partition plate prevents the cooling medium from flowing into the local heating unit. The pipe is used in a state where the pipe is filled with a corrosive substance by forcibly cooling it so that the cooling medium is brought into contact with the pipe inner surface at the portion where the local heating is finished, and the inner surface is subjected to compressive residual stress. Has improved corrosion resistance.

[0003]

In the above prior art, since heating is performed as it is without arranging anything inside the tube corresponding to the local heating section, the heating coil is placed in the large air layer space inside the corresponding tube. However, in order to heat the inside of the tube by convection to heat the inside of the tube to a required high temperature, a large amount of heat is required from the heating coil, and there is a problem that the heat utilization efficiency is low.

An object of the present invention is to provide a heat treatment jig for a container and a heat treatment method for a container, which can simplify the structure and reduce the amount of heat input from the heating means, and can greatly improve the heat utilization efficiency.

[0005]

[Means for Solving the Problems] The above object is to provide a cooling medium so that a cooling medium does not come into direct contact with the local heating inner surface during heating by inserting a jig matching the processing shape of the container on the inner surface of the heating portion of the container. Is achieved by circulating in the container.

That is, the present invention relates to a heat treatment jig for a container, which is arranged in a container in which a heating means locally heats the outside from the outside and the inner surface is cooled by a cooling medium, the jig being formed of a heat insulating material, The medium has a medium passage through which the cooling medium passes, and the tip of the cooling medium in the flow direction is located in the vicinity of the heating means. The part is open, while the upstream side has a closed gap.

Further, the present invention relates to a jig for heat treatment of a container, which is disposed in a container in which a heating means locally heats the outside from the outside and the inner surface is cooled by a cooling medium, the jig being formed of a heat insulating material, It has a medium passage through which the cooling medium passes, the tip in the flow direction of the cooling medium is located in the vicinity of the heating means, and the outer surface around the medium passage is formed so as to contact the inner surface of the container. It is a feature. Here, the tip of the jig is preferably chamfered in a curved shape.

Further, the present invention is a heat treatment processing method for a container in which a compressive residual stress on the inner surface is imparted by cooling the inner surface side corresponding to the local heating portion from the outside by a heating means with a cooling medium. The jig for heat treatment is arranged in the container for performing the local heating, and the cooling medium is caused to flow into the container. The cooling medium is passed through the medium passage of the jig, and the jig and the inner surface of the container. The local heating is performed while forming a high-temperature gas layer based on the heat transfer of the local heating in the gap between and, and immediately after that, the inner surface of the local heating section is forcibly cooled by the cooling medium to give the inner surface compressive residual stress. The local heating and the forced cooling are performed over the entire processed portion of the container.

Further, the present invention is a heat treatment processing method for a container in which an inner surface compressive residual stress is imparted by cooling an inner surface side corresponding to a local heating portion from the outside by a heating means with a cooling medium, corresponding to the local heating portion. The jig for heat treatment is arranged in a container for heating, the cooling medium is caused to flow in the container while the local heating is performed, and the cooling medium passes through the medium passage of the jig, and the jig is made of a heat insulating material. And local heating while contacting the inner surface of the container, and immediately after that, the inner surface of the local heating portion is forcibly cooled by the cooling medium to give a compressive residual stress on the inner surface, and the local heating and the forcible cooling are processed on the container. It is characterized in that it is applied over the entire part. Here, in addition to the inner surface side of the local heating portion, the outer surface side may be forcibly cooled. It is also possible to bend the container while locally heating and forcibly cooling.

[0010]

In the case of using the heat treatment jig in which a gap is formed between the jig and the inner surface of the container, the cooling medium does not flow into the gap. Although the container is locally heated by the external heating means, since the gap is formed on the inner surface corresponding to the local heating portion, the inner surface of the heating portion is not forcibly cooled even with the cooling medium flowing, The heating causes vaporization of the cooling medium in the vicinity of the gap opening portion to cause local boiling to form a high temperature gas layer, and the outer heating means and the inner high temperature gas layer sufficiently heat the container locally. Further, since the jig is formed of a heat insulating material and the gap is a high temperature gas layer space having a very small volume, the amount of heat transferred to the space by convection is very small. Therefore, the amount of heat input from the heating means to the local heating unit can be made smaller than in the conventional case, and the heat utilization efficiency can be improved.

In the case of using a heat treatment jig in which the jig and the inner surface of the container are in contact with each other, the heat escape due to direct convection can be prevented, and sufficient local heating can be performed similarly to the gap structure. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an embodiment of the present invention and shows a plan view of an apparatus for carrying out heat treatment using an induction heating apparatus.
In the figure, 1 is a cylindrical tube to be heat-treated, and 3 is a drive head for axially pressing and driving the tube 1. 4 is an induction heating device equipped with an induction heating coil 4A, 6
Is a fixing head for fixing and supporting the tube 1. The inner surface of the pipe 1 is cooled by a mechanism in which the cooling water a is caused to flow to the inner surface of the pipe by the pump 10, and a heat treatment jig 7 made of a heat insulating material is inserted into the inner heating portion so that the heating portion is not cooled by the cooling water. Has become. That is, the heat treatment jig 7 has the medium passage 15 through which the cooling water a passes, the tip 16 in the flow direction of the cooling water a is located in the vicinity of the induction heating coil 4A, and the outer surface around the medium passage 15 is located. Between the pipe 1 and the inner surface of the pipe 1, the front end portion 16 of the cooling water a in the flow direction is opened, while the upstream side is closed by the bearing 8.
Is formed. Although the position of the tip portion 16 in the flow direction of the heat treatment jig 7 is in the vicinity of the induction heating coil 4A, it is preferably formed so as to project at least slightly downstream from the position of the induction heating coil 4A. Thereby, the gap can be surely formed inside the local heating unit.

If the induction heating coil 4A and the jig 7 are of a stationary type and the pipe 1 is moved while the fulcrum members 2 and 2A are kept in a fixed position, the cooling water a is immediately cooled from the inner surface immediately after the local heating. The inner surface of the tube can improve residual stress and metallography over the entire length of the tube. The advantage of this is that since it is locally heated, the deformation of the pipe is small and the deformation correcting process after the pipe processing can be omitted.

On the inner surface of the portion heated by the induction heating coil 4A, the cooling water a is vaporized to cause local boiling because the cooling water is prevented from entering by the jig 7, and the same temperature as the outer surface is obtained. I was able to hold. The material of the jig 7 is selected under the condition that heat from the pipe 1 is not conducted to the jig 7, and the cooling water a circulating on the inner surface a
This prevents the jig 7 from being cooled. The relationship between the clearance h and the outer diameter d ₁ of the jig 7 and the heat input amount S by the induction heating coil 4A can be expressed by the following two equations as long as the cooling water is boiled.

[0015]

## EQU1 ## h = (d ₂ −d ₁ ) / 2

[0016]

[Formula 2] S ≧ π / 4 · (d ₂ ² −d ₁ ² ) · x · γ · (h ₂ −h ₁ ) where d ₂ is the inner diameter of the pipe 1 and d ₁ is the outside of the jig 7. The diameter, x is the heating width, γ is the specific gravity of the cooling water a, h ₁ is the enthalpy of the initial temperature of the cooling water a, and h ₂ is the enthalpy of the boiling temperature of the cooling water a. Using Equation (1), the gap h, which is the boiling limit, is obtained, and the outer diameter d ₁ of the jig 7 is obtained. Since the temperature of the inner surface and the outer surface of the tube 1 is made uniform by inserting the jig 7,
For example, bending is performed while heating the alloy components of steel to a temperature at which it is dissolved in the solid solution or higher, and rapid cooling can also perform the solid solution treatment at the same time, which can improve the metal structure of the inner surface of the pipe and omit the solution heat treatment. can do.

FIG. 2 shows an embodiment in which a heat treatment jig is used in which the jig 7 contacts the inner surface of the container. Since there is no gap 17 in the embodiment shown in FIG. 1 and heat escape can be directly prevented, and local heating can be sufficiently performed as in the gap structure.

FIG. 3 shows a plan view of an apparatus for carrying out the induction heating tube bending method. In the figure, 1 is a pipe to be bent,
Reference numerals 2 and 2A are tube bending fulcrum members, and 3 is a drive head for pressing the tube 1 in the axial direction. 4 is an induction heating device equipped with an induction heating coil 4A, 11 is a fixed head,
The tube 1 attached to the free end of the rotary arm 5 having a predetermined radius that rotates about the center of rotation 9 is fixed and supported. The bending fulcrum members 2 and 2A of the tube 1 and the induction heating device 4 are attached by the rotating arm 5 and the fixing head 11 in the vicinity of the position where bending is performed. The cooling of the inner surface after processing has a mechanism in which the cooling water a is circulated to the inner surface of the pipe by the pump 10. A jig 7 similar to the embodiment shown in FIG.
Are arranged in the tube 1.

When the pipe 1 is bent by this pipe bending apparatus, the fixing head 11 of the rotary arm 5 is fixed to the pipe 1 in the vicinity of the induction heating coil 4A, and then the pipe 1 is locally heated by the induction heating coil 4A. On the other hand, the drive head 3 presses and drives the tube 1 in the arrow direction at a constant speed. When the tube 1 is heated and softened, it is pressed in the axial direction and is fixed and supported by the fixing head 11 of the rotating arm 5, so that the tube 1 is rotated by the rotating arm 5.
Bending is performed with a radius R around the rotation center 9 of. The solid line positions of the rotary arm 5 and the fixing head 11 in FIG. 3 show a state in which processing is performed from the bending processing fulcrum to this point. During the bending process of the pipe, the pipe 1 is bent by the bending fulcrums 2 and 2A so that the pipe 1 can be smoothly bent without being displaced.

After the working, the cooling water a is circulated by the pump 10 on the inner surface to cool the bent portion in order to apply compressive residual stress on the inner surface by quenching the inner surface. Since the cooling water a on the inner surface cools the heated portion on the inner surface, it has been conventionally difficult to reach the bending temperature and excessive heating is required. However, according to the present invention, the jig 7 is provided inside the locally heated portion. Inserted,
The heating performance is enhanced in the same manner as described in the above embodiment. The driving of the tube 1 by the driving head 3 is performed by moving the driving head 3 with the tube 1 fixed. Then, heating and driving of the tube 1 are continuously performed.
In the case of bending, as shown in the figure, when the rotary arm 5 and the fixing head 6 are at the dotted line position F, the pipe 1 is subjected to a high temperature bending deformation with a radius of gyration R, and the work is completed. Then, the driving distance of the tube 1 by the driving head 3 and the bending radius R by the rotating arm 5
By adjusting, it is possible to manufacture a bent pipe having an arbitrary bending angle and bending radius.

FIG. 4 shows in detail the shape of the jig 7 to be inserted into the inner surface of the pipe to be bent. The jig 7 is
To improve the heating performance of the heating part, there is always a gap h between the inner surface of the pipe 1 and
It is desirable that the shape of the tip of the jig 7 is adjusted to the bending radius so that the gap h is always maintained even when the bending process is started and bent. That is, the tip portion 16 of the jig 7 is chamfered in a curved shape. Further, in order to maintain a gap h with the tube 1, it is desirable to keep the bearing 8 made of a material softer than the tube 1 outside the range of the heating section by the induction heating coil 4A.

In the bending apparatus shown in FIG. 3, the inner surface of the pipe is rapidly cooled after the bending work to positively give a compressive residual stress to the inner surface of the pipe to improve the corrosion resistance of the inner surface. As an application example of this, FIG. 5 shows a plan view of a bending apparatus for simultaneously cooling the inner and outer surfaces. The outer surface cooling element 14 is attached to the apparatus of FIG. 3 in the vicinity of the induction heating coil 4A, and after bending, the inner and outer surfaces are simultaneously cooled. Since the jig 7 is inserted, simultaneous cooling of the inner and outer surfaces can be easily performed by adjusting the spraying position of the cooling water a of the outer surface cooling element 9 to the tip position of the jig 7. By this simultaneous cooling of the inner and outer surfaces, compressive residual stress can be positively applied to the inner and outer surfaces of the pipe as shown in FIG. 6, so that the corrosion resistance strength of the pipe used when the inner and outer surfaces of the pipe are filled with a corrosive substance is improved. You can This method also enables heat treatment of a straight pipe by adding the outer surface cooling element 14 to FIG.

As another embodiment of the heat treatment of the pipe of the present embodiment, FIG. 7 shows a plan view of a heat treatment apparatus for a pipe for locally cooling the inner surface. In FIG. 1, the cooling water a is circulated on the inner surface, but in the embodiment of FIG. 7, it is attached to the induction heating coil 4A, the jig 7 and the small diameter tube 12 penetrating the medium passage of the jig 7 and the tip thereof. Since the inner surface local cooling element 13 is a stationary type and the tube 1 is moved while maintaining the fixed position by the fulcrum members 2 and 2A, the inner surface local cooling element 13 locally cools the cooling water a immediately after heating, The inner surface of the straight pipe can improve the residual stress and the metal structure over the entire length of the pipe, and the same performance as that of FIG. 1 is obtained. Further, it is also possible to substitute the cooling water a with, for example, air.

[0024]

As described above, according to the present invention, the amount of heat input from the heating means to the local heating portion can be made smaller than in the conventional case, and the heat utilization efficiency can be improved. Further, it also has the effect of eliminating the need for solution heat treatment and the effect of imparting residual stress.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an apparatus for performing heat treatment on an inner surface using an induction heating apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view showing an apparatus for performing heat treatment on an inner surface using an induction heating apparatus according to the present invention.

FIG. 3 is a schematic cross-sectional view showing an induction heating pipe bending apparatus according to the present invention.

FIG. 4 is a cross-sectional view showing in detail the shape of a heat treatment jig of one embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of an apparatus for performing heat treatment on inner and outer surfaces using an induction heating device according to the present invention.

FIG. 6 is a diagram showing a residual stress distribution after heat treatment on the inner and outer surfaces.

FIG. 7 is a schematic cross-sectional view of an apparatus for performing heat treatment on an inner surface according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 pipe (container) 2 fulcrum member 2A fulcrum member 3 drive head 4 induction heating device 5 rotating arm 6 fixing head 7 jig for heat treatment of container 11 fixing head 14 external surface local cooling element 15 medium passage 16 tip portion 17 gap

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kazumi Anazawa 3-1-1, Saiwai-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Takehiko Minami 3-chome, Saiwai-cho, Hitachi, Ibaraki No. 2 within Hitachi Engineering Services Co., Ltd. (72) Inventor Nobuyuki Kajiya 3-2-2, Saiwaicho, Hitachi City, Ibaraki Prefecture Within Hitachi Engineering Services Co., Ltd.

Claims (7)

[Claims] 1. A heat treatment jig for a container, which is disposed in a container in which a heating means locally heats the outside from the outside and the inner surface is cooled by a cooling medium, wherein the jig is formed of a heat insulating material. Has a medium passage through which a flow direction tip of the cooling medium is located in the vicinity of the heating means, and the flow direction tip of the cooling medium is open between the outer surface around the medium passage and the inner surface of the container. On the other hand, the jig for heat treatment of the container is characterized in that the upstream side is formed to have a closed gap. 2. A jig for heat treatment of a container, which is disposed in a container in which a heating means locally heats the outside from the outside and an inner surface is cooled by a cooling medium, wherein the jig is formed of a heat insulating material. Has a medium passage through which the tip of the cooling medium in the flow direction is located in the vicinity of the heating means,
A jig for heat treatment of a container, wherein an outer surface around the medium passage is formed so as to come into contact with an inner surface of the container. 3. The heat treatment jig for a container according to claim 1 or 2, wherein a tip end portion of the jig is chamfered in a curved shape. 4. A heat treatment processing method for a container, wherein an inner surface compression residual stress is applied by cooling an inner surface side corresponding to a local heating portion from the outside by a heating means with a cooling medium, in the container corresponding to the local heating portion. Claim 1 or 3
The heat treatment jig as described in 1 above is disposed, and the cooling medium is caused to flow into the container while performing the local heating, and the cooling medium is allowed to pass through the medium passage of the jig, and between the jig and the inner surface of the container. The local heating is performed while forming a high-temperature gas layer based on the heat transfer of the local heating in the gap, and immediately after that, the inner surface of the local heating unit is forcibly cooled by the cooling medium to give the inner surface compressive residual stress, and the local portion A heat treatment processing method for a container, characterized in that heating and forced cooling are performed over the entire portion of the container to be processed. 5. A heat treatment processing method for a container in which an inner surface compressive residual stress is applied by cooling an inner surface side corresponding to a local heating portion from the outside by a heating means with a cooling medium, in the container corresponding to the local heating portion. Claim 2 or 3
The heat treatment jig described in 1 above is provided, and the cooling medium is caused to flow into the container while performing the local heating, and the cooling medium is passed through the medium passage of the jig, and the jig made of a heat insulating material and the container. The local heating is performed while contacting the inner surface, and immediately after that, the inner surface of the local heating section is forcibly cooled by the cooling medium to give a compressive residual stress on the inner surface, and the local heating and the forcible cooling are applied to the entire processed portion of the container. A method for heat-treating a container, which is characterized in that the treatment is performed over the entire area. 6. The heat treatment processing method for a container according to claim 4 or 5, wherein not only the inner surface side of the local heating portion but also the outer surface side is forcibly cooled. 7. The heat treatment processing method for a container according to claim 4, wherein the container is bent while the local heating and forced cooling are performed.